Soyuz 4

Soyuz 4

Model of Soyuz 4 and Soyuz 5 after performing the first docking of two manned spacecraft on 16 January 1969
Mission type	Test flight
Operator	Soviet space program
COSPAR ID	1969-004A
Mission duration	2 days, 23 hours, 20 minutes, 47 seconds
Orbits completed	48
Spacecraft properties
Spacecraft type	Soyuz 7K-OK(A)
Manufacturer	Experimental Design Bureau OKB-1
Launch mass	6,625 kilograms (14,606 lb)
Crew
Crew size	1 up 3 down
Members	Vladimir Shatalov
Landing	Aleksei Yeliseyev Yevgeny Khrunov
Callsign	Амур (Amur - "Amur River")
Start of mission
Launch date	14 January 1969, 07:30:00 (1969-01-14UTC07:30Z) UTC
Rocket	Soyuz
Launch site	Baikonur 31/6[1]
End of mission
Landing date	17 January 1969, 06:50:47 (1969-01-17UTC06:50:48Z) UTC
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Perigee	213 kilometers (132 mi)
Apogee	224 kilometers (139 mi)
Inclination	51.7 degrees
Period	88.8 minutes
Docking with Soyuz 5
Docking date	16 January 1969, 08:20 UTC
Undocking date	16 January 1969, 12:55 UTC
Time docked	4 hours, 35 minutes
Soyuz programme (Manned missions)

Soyuz 4 (Russian: Союз 4, Ukrainian: Союз 4, Union 4) was launched on 14 January 1969, carrying cosmonaut Vladimir Shatalov on his first flight. The aim of the mission was to dock with Soyuz 5, transfer two crew members from that spacecraft, and return to Earth. The previous three Soyuz flights were also docking attempts but all had failed for various reasons.

The radio call sign of the crew was Amur, while Soyuz 5 was Baikal. This referred to the trans-Siberian railway project called the Baikal-Amur Mainline, which was under construction at the time. The mission presumably served as encouragement to the workers on that project.

Crew

Backup Crew

Reserve Crew

Mission parameters

• Mass: 6,625 kg (14,606 lb)
• Perigee: 213 km (132 mi)
• Apogee: 224 km (139 mi)
• Inclination: 51.7°
• Period: 88.8 min

Space walk

• Yeliseyev and Khrunov - EVA 1
• EVA 1 start: 16 January 1969, 12:43:00 UTC
• EVA 1 end: 16 January 13:15 UTC
• Duration: 37 minutes

Mission highlights

The Soyuz 4 and 5 spacecraft docked on 16 January, the first time two manned spacecraft had docked (Apollo 9 would do the same in March of the same year). The two craft possessed only a primitive probe (Soyuz 4) and drogue (Soyuz 5) docking assembly. A connecting tunnel for the docking mechanism had not yet been developed, which prevented a simple internal transfer between the craft. This required the two transferring cosmonauts to spacewalk from one vehicle to the other. Aboard Soyuz 5, Yevgeny Khrunov and Aleksei Yeliseyev immediately began preparing for their extra-vehicular activity (EVA). Boris Volynov, who would remain aboard Soyuz 5, filmed them donning their Yastreb space suits.

On their 35th revolution of Earth, the two cosmonauts exited the spacecraft for the second Soviet spacewalk. One of Khrunov's lines became tangled and he accidentally closed the tumbler of his suit ventilator. This distracted Yeliseyev who did not set up the movie camera on the orbital module before exiting the spacecraft. As such, there is no film of the historic EVA, only a poor video transmission.

One hour later, the two were greeted by Shatalov after the repressurisation of the Soyuz 4 orbital module, which also acted as an airlock. Soyuz 4 and 5 separated after 4 hours and 35 minutes docked together. Soyuz 4 re-entered the atmosphere and landed 100 kilometers (62 mi) southwest of Karaganda on 17 January 1969.

The mission proved it was possible to perform the activities that would be needed on a Soviet lunar landing. The Soviet plan called for a lone cosmonaut to land on the moon, return to lunar orbit, then make a spacewalk back from the landing craft to the orbiting spacecraft after docking. This was because there was no internal tunnel between the two craft as found on the American Apollo CSM and LM.

The crew were to meet Leonid Brezhnev during a lavish ceremony at the Kremlin, but this was prevented by an attempted assassination of the Soviet leader. A man shot eight times at the motorcade but aimed at the car containing Georgi Beregovoi, Alexei Leonov, Andrian Nikolayev, and Valentina Tereshkova. They were unharmed but Brezhnev's car was forced to speed away past the waiting Soyuz 4/5 crews on the podium.

EVA details

The docking mission had EVA objectives similar to those planned for Apollo 9. Soyuz 4 launched first, and was the active vehicle in the docking with Soyuz 5. The news agency TASS stated that: "there was a mutual mechanical coupling of the ships . . . and their electrical circuits were connected. Thus, the world’s first experimental cosmic station with four compartments for the crew was assembled and began functioning." The mission rehearsed elements of the Soviet piloted lunar mission plan. Moscow TV carried the cosmonauts’ EVA preparations live. Khrunov and Yeliseyev put on their Yastreb ("hawk") suits in the Soyuz 5 orbital module with aid from Commander Boris Volynov.

Yastreb suit design commenced in 1965, shortly after Alexei Leonov’s difficult EVA. Leonov served as a consultant for the design process, which was completed during 1966. Suit fabrication and testing occurred in 1967, but the fatal Soyuz 1 accident in April of that year and docking difficulties on the joint Soyuz 2-Soyuz 3 mission delayed its use in space until Soyuz 4-Soyuz 5.

To prevent the suit ballooning, the Yastreb suit featured a pulley-and-cable articulation system. Wide metal rings around the gray nylon canvas undersuit's upper arms served as anchors for the upper body articulation system. The Yastreb had a regenerative life support system in a rectangular white metal box placed on the chest and abdomen to facilitate movement through the Soyuz's hatchways.

Volynov checked out Khrunov and Yeliseyev’s life support and communications systems before returning to the descent module, sealing the hatch, and depressurizing the orbital module. Khrunov went out first, transferring to the Soyuz 4 orbital module while the docked spacecraft were out of radio contact with the Soviet Union over South America. Yeliseyev transferred while the spacecraft were over the Soviet Union. They closed the Soyuz 4 orbital module hatch behind them, then Soyuz 4 Commander Vladimir Shatalov repressurised the orbital module and entered to help Khrunov and Yeliseyev get out of their suits. The spacewalkers delivered newspapers, letters, and telegrams printed after Shatalov lifted off to help prove that the transfer took place.

See also

• List of spacewalks

References